Laundry machine



Au8 15 1951 K. w. NEIDENTHAL ETAL 2,995,918

LAUNDRY MACHINE POSlTION OF CENTER OF GRAVITY OF UNBALANCED LOAD,

IN PERCENT OF AXIAL DEPTH OF CHAMBER 83 AWAY FROM OPTIMUM PLANE 84 IN VUV TORS n KENNETH w. NEIDENTHAL JAMES E. BALLMER 2 ALBERT M. RocKwooDATTORNEYS awww K. w. NEIDENTHAL ETAL 2,995,918

Aug. 15, 1961 LAUNDRY MACHINE Filed Jan. ll, l 57 INVENTORJ KENNETH W.NEIDENTHAL JAMES E. BALLMER ATTORNEYSA ALBERT M. ROCKWOOD BY OOOOOOOOOOO OOOOOO OOOOOOO United States Patent O 2,995,918 LAUNDRY MACHINEKenneth W. Neidenthal, Columbus, Ohio, James E. Ballmer, Fort Worth,Tex., and Albert M. Rockwood, Columbus, Ohio, aignors, by mesneassignments, to McGraw-Edison Company, Elgin, lll., a corporation ofDelaware Filed Jan. 11, 1957, Ser. No. 633,595 8 Claims. (Cl. 68-24)This invention relates to laundry machines, particularly to machines forwashing laundry and centrifugaL ly extracting duid therefrom, and tomachines used only for centrifugal extraction of uid from articlesplaced therein.

A primary object of the present invention is to provide a laundrymachine that can be operated at high speeds of rotation for extractionof fluid from articles theren'without requiring that the base of thelaundry machine be fastened to the floor on which it stands. Otherobjects and advantages are apparent from the disclosure herein.

'Ihe etlciency and speed of extraction of uid from laundry are increasedrapidly with increasing speed of rotation of the laundry. In the past ithas been necessary to operate-extractors at relatively low speeds ofrotation, or else to bolt them to the floor. The present in- -ventionmakes possible the use of much higher operating speeds in a laundrymachine that need not be bolted to the door.

iin a laundry machine that is not fastened to the oor, all operatingspeeds must bebelow the speed at which the base of the machine may movewith respect to the floor. To minimize the forces on the base of alaundry machine during rotation, it is customary to make the rotatingstructure symmetrical about its axis of rotation. During a substantialportion of the time, however, the laundry inside the machine is notevenly distributed about the axis of rotation, and the composite centerof gravity of the laundry ordinarily is located at a substantialdistance from the axis of rotation. 'Ihe unbalance introduced into themachine by the laundry results in undesirable forces, the effects ofwhich must be minimized in order to make possible the use of highoperating speeds of rotation.

ln a preferred form of laundry machine according to the presentinvention the axis of rotation is substantially horizontal. Thecomposite center of gravity of the laundry spinning about a horizontalaxis cannot conveniently be made to coincide with the axis of rotation,but it can be made to lie approximately in a given vertical planeperpendicular to the axis of rotation. It has been found as a part ofthe present invention that in a laundry machine having a suspendedassembly, including a rotatable member, connected at one end to asupporting vframe by a universal pivot, and resiliently supported at aPatented Aug. 15, v1961 ICC pivot, plus approximately 11 percent of theaxial depth of the chamber in the suspended assembly in which thelaundry is located. The composite center of gravity of the laundryshouldl be within about 18 percent, and preferably Within about 14percent, of the axial depth of the chamber of the optimum plane.

Best results are obtained where the universal pivot comprises twoperpendicular pivotal connections. Preferably friction means engageableat each pivotal connection are provided for reducing the gyration of thesuspended assembly during rotation of the rotatable member while passingthrough the critical speeds. The resilient supporting means preferablyshould be a soft compression spring providing a substantially verticalupward force through the axis of rotation. The soft spring has a lownatural resonant frequency and thus provides low critical speeds ofrotation, so that the exciting forces resulting from the unbalancedlaundry load are relatively low at the critical speeds.

In accordance with the above and other features of the presentinvention, a preferred embodimentV of a centrifugal extractor includes asupporting frame and a 'suspended assembly connected at one end to theframe by a universal pivot. The suspended assembly comprises an outercontainer and an inner container therein, each substantially symmetricalabout a substantially horizontal axis. Resilient supporting meansconnected to the frame supports the suspended assembly at a positionaway from the pivot. Means are provided for rotating the inner containerabout the axis.

Means which may include the resilient supporting means and the chamberin the inner container are provided for positioning articles in thechamber with the composite center of gravity of the articlesapproximately in an optimum plane perpendicular to the axis at adistance from the pivot equal to the moment of inertia of the suspendedassembly divided by the product of its mass and the distance from itscenter of gravity to the pivot, plus approximately 1l percent of theaxial depth of the chamber. The composite center of gravity of thearticles should be within about 18 percent, and preferably within about14 percent of the axial depth of the chamber of the optimum plane.

Friction means engageable with the universal pivot preferably areprovided for reducing the gyration of the suspended assembly duringrotation of the inner container while passing through a critical speed.The universal pivot preferably comprises two perpendicular pivotalconnections including a trunnion member connected to the suspendedassembly and pivotably received by a horizontal bearing in the universalpivot connector and a vertical shaft in the universal pivot Vconnectorpivotably received by a bearing in the frame, -the pivot axis in theframe intersecting the pivot axis of the trunnion member. The frictionmeans are engageable with each pivotal connection.

The resilient supporting means preferably comprises a compression springconnected to the frame and supporting the suspended assembly, at aposition away from the pivot, from beneath the suspended assembly byproviding a substantially vertical upward force through thesubstantially horizontal axis of rotation. The compression springpreferably is so constructed as to provide a higher critical speed ofrotation for the inncr container of less than about 90 revolutions perminute.

Resilient positioning means are connected between the frame and thesuspended assembly at a position circumferentially spaced from theresilient supporting means` for confining thc gyration of the suspendedassembly to positions substantially above the resilient supportingmeans.

A laundry machine for washing laundry as well as centrifugallyextracting washing liuid from the laundry preferably includes also asupport member, connected to the frame in aY position to support andrestrain the gyration of the suspended' assembly during washing, theposition of the support member being beyond lthe range of gyration ofthe suspended assembly during extraction.

In the drawings:

FIG. 1 is a front view, partially cut away and partially in section, ofa laundry machine according to the present invention;

FIG. 2 is a side view, partially cut away and partially in section, ofthe laundry machine of FIG. l;

FIG. 3 is'a sectional view of a portion of the laundry machine, takenalong the line 3 3 of FIG. 2;

FIG. 4 is a sectional Aview of a portion of the laundry machine, takenon the line 4 4 of FIG. 2. To facilitate understanding7 FIG. 4 islocated in orthographicprojection both with FIG. 2 and with FIG. 3, and

FIG. is a graph, in rectangular coordinates, of the maximum usefuloperating speed against the position of the center of gravity of anunbalanced load in the laundry machine, illustrating an importantfeature of the invention.

Referring particularly to FIGS. 1 and 2, a preferred form of laundrymachine 10 according to the present invention includes a supportingframe 11. The supporting frame 11 comprises base members 1212 lixedlyconnected together as shown, as bywelding; side support members 13-13xedly connected to the base members 12-12 as shown, as by welding; andrear support members 14-14 lixedly connected together and to the basemembers 12- 12 as shown, as by welding.

Mounted on the horizontal rear frame members 14-14 is a universal pivot15. (See also FIGS. 3 and 4.) Fixedly connected to the horizontal rearframe members 14-14 are upper and lower plates 16-16 which receive upperand lower bearing sleeves 17-17 respectively, The sleeves 17-17 togetherprovide a vertical bearing 18 in which is placed a vertical shaft 19 ofthe universal pivot 15.

Engageable with an extension 20 that is xedly connected to the lower endof the vertical shaft 19 is a horizontal damper 21, which provides africtional force to oppose horizontal rotation of the vertical shaft 19.The horizontal damper 21 includes a pivot pin 22 connected to the lowerplate 16 and pivotably holding one end of a sickle shaped brake arm 23,to the inner surface of which is attached a friction liner 24 made ofsuitable friction material such as ordinary brake liner material. Abracket 25 xedly connected to the lower plate 16 is provided with acylindrical hole 26 in line with a similar hole 27 in the brake arm 23.A bolt 28 through the holes 26, 27 is held in place by a nut 29. Acompression spring 30 mounted on the bolt 28 between the head 31 of thebolt 28 and the straight end of the arm 23 presses the arm 23 toward'theshaft extension 20, and thereby presses the lining 24 against the shaftextension 20.

Fixedly connected at its center to the upper end of the vertical shaft19 is a horizontal support plate 32, to two opposite ends of which aretixedly connected vertical brackets 33-33. In each bracket 33 is mounteda horizontal sleeve bearing 34 (FIG. l) which serves as a bearing for ahorizontal trunnion'member 35. Each trunnion member 35 is fixedlyconnected as by a pin connection 36 to one end of a tub extension 37,the other end of which is xedly connected to the rear plate 38 of anouter container or tub 39. At the outwardly projecting end of eachtrunnion member 35 is xedly connected a cylindrical end disk 40.

A vertical damper 4l frictionally engageable with the l end disk 40 ofthe trunnion 35 is mounted on each bracket 33. The vertical damper 41includes a pivot pin 42 xcdly connected to the bracket 33 and pivotablyholding a pair of sickle-shaped brake arms 43-43 oppositely disposedabout the trunnion member 35 and surrounding the end disk 40. Attachedto the inner surfaces of the brake arms 43-43 are friction liners 44-44made of suitable friction material such as brake liner material. A bolt45 passing through cylindrical holes 46-46 in the straight ends of thebrake arms 43-43 and held in place by a nut 47 presses the brake arms43-43 toward each other by means of a compression spring 48 mountedaround the bolt 45 between the head 49 of the bolt 45 and the straightend portion of one brake arm 43. Thus friction liners 44-44 are pressedinto frictional engagement ywith the end disk 40 of the trunnion member35. The vertical dampers 41-41 oppose vertical motion of the tub 39about the horizontal axis of the trunnion members 35-35 inthe horizontalbearings 34-34. The horizontal pivot axis of the trunnion members 35-35intersects the vertical pivot vaxis of the vertical shaft 19.

Connected .to the perimeter of the rear plate 38 of the tub 39 is oneend of a cylindrical tub body 50, to the opposite end of which isconnected a front face member 51 of concentric rib construction. A door52 which may include a transparent central portion 53 is pivotablymounted, as by a hinge connection 54, in the center of the front face 51of the tub 39. Conventional locking means, such as a handle and slot asindicated at 55, are provided to hold the door 52 shut during operation.The central portion 53 of the door 52 projects into the tub 39 asubstantial distance. K i

An inlet pipe 57 connected to a source of water supplies water to thetub 39. A receptacle 58 in the tub 39 is provided for supplyingdetergent to the laundry machine 10. A drain outlet 59 at the bottom ofthe tub 39 provides for drainage of the laundry uid and rinse waterduring the washing and rinsing cycles.

A main support spring 60, mounted between an upper receptacle 61connected to the tub 39 and a lower receptacle 62 connected to the frame11, resiliently supports the tub 39 except when, as during washing andrinsing, the tub 39 contains a substantial quantity of water sufcient toforce it down against the compression force of the spring 60 to a stiftU-shaped spring 63 which is tixedly connected to the upper end of avertical support member 64 the lower end of which is xedly connected tothe frame 11.

The tub 39 is resiliently held in a central position bctween the sideframe members 13-13 by a pair of centering springs 65--65 each of whichis connected at end by a hook member 6'6 to the adjacent side framemember 13 and at the opposite end by a hook member 67 to the rearextension member 37 of the tub 39.

An inner container or cylinder is coaxially mounted inside the outercontainer or tub 39, The cylindrical body 71 of the cylinder 70 is xedlyconnected to aat rear wall 72 and to a at front wall 73. The front wall73 has a circular central opening just large enough to provide a smallclearance around the inner portion 53 of the door 52 which projectsinwardly just beyond the plane of the front wall 73 of the innercontainer 70. The cylinder body 71 includes a plurality of inwardlyprojecting vanes 74-74, preferably three or four, equally spacedcircumferentially in the inner container 70. Perforations 75-75 areprovided in the vanes 74-74 as well as in the cylindrical body 71. Abacking ring 76 and a ribbed reinforcing plate v77 are xed'ly connectedto the rear of the cylinder body 71 and to the rear wall 72 of the innercontainer 70. The ribbed plate 77 is tixedly connected to one end of adrive shaft 78 which is rotatably mounted in the tub extension 37through a rotary seal 69 and a bearing 79.

The opposite end of the .shaft 78 extends beyond the universal pivot andis fixedly connected to pulleys Sil-80, which may be driven by aconventional motor I and belt drive (not shown) which may beconveniently mounted on the frame 11 below. The axis 82 of the driveshaft 78, which is also the axis of symmetry of the entire innercontainer 70 and the axis of symmetry of the entire outer container 39,is substantially horizontal and perpendicularly intersects the axis ofthe vertical shaft 19 and the axis of the horizontal trunnions 35--35 ofthe universal pivot 15, as is indicated at 85.

The outer container 39 and the inner container 70; which includeeverything mounted in the universal pivot 15, supported by the supportspring 60, and centered by the tension springs 65-65; comprise asuspended assembly 81A that is substantially symmetrical about itssubstantially horizontal axis 8,2.,v which coincides with the axis ofthe shaft 78.

The chamber 83, formed by the cylinder body 7l, the rear wall 72, andthe front wall 73, is constructed and positioned so. as to position anylaundry placed therein with the composite center of gravity of thelaundry approximately inthe optimum plane 84 which is perpendicular tothe axis 82 at afdistance from the universal pivot 15 (the distancebeing measured from the intersection of the pivot axes at 8S) equal tothe moment of inertia of the suspended assembly 81 divided by theproduct of'its mass and the distance from its center of gravity,indicated at 86. to the pivot 15. plus approximately ll percent of theaxial depth (the distance between the front wall 73 and the rear wall72) of the chamber 83.

ln the preferred form of laundry machine 10 illustrated in FIGS. l and2,. the chamber 83 is cylindrical and is located with its axissubstantially horizontal. Thus the composite center of gravity of thelaundry therein is located approximately midway between the front wall73Y and the rearV wall 72. The chamber 83 istherefore located withitsmid-plane approximately coinciding with theoptimumplane 84. The mainsupport spring 60 preferably is located approximately below the centerof gravity 86 of the suspendedassembly 81, to provide optimum support ofthe weight, and its length and stiffness are selected so as to maintainthe axis of rotation 82 approximately horizontal during extraction, whenmost of the water used during washing and rinsing has been removed fromthe tub 39. if it were desired to perform the extraction operation withthe suspended assembly tipped forward orbackward at a substantial angle,the cornposite center of gravity ofthe laundry would be shifted forwardor backward and the location of the chamber 83 would be modifiedaccordingly to locate the composite center of gravity approximately' inthecptimum plane 84. One ormore of the walls 71. 72. 73l of thecontainer 83 could be made arcuate in shape, if desired, particularly ifthe axis of rotation 82 were to be located at an angle to thehorizontal. l Many other obvious means for positioningthe laundry in thechamber 83 could of course be used if desired.

Opernlion The articles to be washed and spin-dried are placed in theChamber 8 3 of the inner container 7G and the door 52 is Yclosed andfastened shut. The laundry machine 10 may utilize any conventionalmanual or automatic controis or .combinations thereof to supply waterand detergent to the tub 39; to drive the inner container 70 through theshaftV 78 to provide the customary washing and rinsing cycles at a slowspeed of the order of 40 revolutions perminute; to drain the washingwater and rinsing water and distribute the laundry at the appropriatetimes at an intermediate speed of the order of 80 revolutions perminute; and, after the washing and rinsing cycles, to rotate the innercontainer 70 at a high speed, in the order of 750 to 900 revolutions perminute, for the spin-drying or extraction of the water retained by thelaundered articles.

During the washing and rinsing, when a substantial amount of water ispresent in the tub 39 the suspended assembly 81 rests on the stiffU-shape'd spring 63. 'I'he rotation of the inner container 70is slowenough that the suspended assembly 81 does not tend to gyrateappreciably about the pivot 15, and the suspended assembly 81 remains inContact with the stili spring 63 duringv washing and rinsing. When thebulk of the water is removed from the tub 39, the main support spring 60forces the suspended assembly 81 upward oi the stiff spring 63, as shownin FIG. 2, and supports the assembly 81 during the high speed rotationfor extraction of the liquid retained in the laundered articles. thechamber 83 positions the laundered articles with their composite centerof gravity approximately in the optimum plane 84, the reaction at theyuniversal pivot 15 from the gyration of the suspended assembly 81 isminimized.

The main support spring 60 is a soft compression spring so constructedas to provide a lower critical speed of rotation preferably of the orderof l5 revolutions per minute and a higher critical speed of rotationpreferably of the order of 60 revolutions per minute. speeds are thoseat which, because of natural resonance conditions, the gyration of thesuspended assembly 81 is greatest, By using a supporting spring 60 thatprovides low critical speeds this gyration is much smaller than it wouldbe if the critical speeds were higher, because the exciting forces fromthe unbalanced laundry load are lower at lower speeds of rotation. Thelaundry machine 10 is not operated at either of the critical speeds butmust pass through these speeds momentarily before reaching the operatingspeeds. While the critical speeds mentioned above are preferable,critical speeds of up to about revolutions per minute may be usedwithout encountering excessive gyration.

While the universal pivot 15 permits gyration of thei' suspendedassembly 81 about the pivot 85, the suspended assembly 81 does notcontact the stifl` spring 63 during the extraction cycle. The minimizingof the effect of ythe gyration on the supporting frame 11 by positioningthe ,i

composite center of gravity of the laundered articles approximately inthe optimum lplane 84 make it possible to use higher speeds of rotationduring extraction than would otherwise be possible without bolting theframe 11 to the oor. Thus rapid, efficient extraction is obtained with alaundry machine that neednot be bolted to the licor.

Numerous tests were made of a laundry machine 10 as shown in thedrawings. The diameter of the chamber 83 was 3() inches and its axialdepth was l5 inches. In each test a load weighing l0 pounds was placedin the chamber 83 with its center of gravity approximately 14% inchesfrom the axis of rotation 82. This provided an unbalanced load conditionmore severe than that obtained with any load of laundry that would beplaced in the chamber. The tests were made with the center of gravity ofthe unbalanced load at various distances from the optimum plane 84.During each test run the load was fastened in place to maintain itscenter of gravity in a definite predetermined location. Beginning at alow speed,v in cach test the speed of rotation was gradually increaseduntil the etectvof the gyration of the suspended assembly 81 resultingfrom the unbalanced laundry load was sutiicient to begin to move thebase 11 of the laundry machine 10 with respect to the floor. The curves88-88 of FIG. 5 show the results of the tests. mum useful operatingspeed, in revolutions per minute (the speed above which the base 11laundry machine 10 may move with respect to the floor), is plottedagainst the position of the composite center of gravity of the flaundry, in percent of the axialdepth of the chamber 83 away from theoptimum plane 84.

Because v The critical.

In FIG. 5 the maxi- As is apparent from the curves 8888 in FIG. S,operating speeds of at least 900 revolutions per minute can be usedwithout causing the laundry machine 10 to move on the oor when thecomposite center of gravity of the articles in the chamber 83 is keptwithin about 14 percent of the axial depth of the chamber 83 of theoptimum plane 84. When the composite center of gravity of the articlesis maintained within about 18 percent of the ial depth of the chamber83, speeds up to 750 revolutions per minute may be used. For a smallerload unbalance the maximum useful operating speed curves lie generallyabove the curves 88--88 of FIG. 5. As the distance from the optimumplane 84 increases, the maximum useful operating speed drops offrapidly. Thus it is clear that the location of the composite center ofgravity of the laundered articles in the chamber 83 is critical, andmust be maintained in the vicinity of the optimum plane 84 to permit themost efficient high-speed extraction.

Where it is desired to use the laundry machine 10 only as a centrifugalextractor, the inlet pipe 57, the detergent receptacle 58, the stiffsupport spring 63, and the vertical support member 64 can be omitted.

' To summarize, a centrifugal extractor l0 according to the presentinvention includes a supporting frame 11, and a suspended assembly 8lconnected at one end to the frame 11 by a universal pivot 15. Thesuspended assembly 81 comprises an outer container 39 and an innercontainer 70 therein, each substantially symmetrical about asubstantially horizontal axis 82. Resilient supporting means 60connected to the frame 11 supports the suspended assembly 81 at aposition 61 away from the pivot 15. .Means 78, 80 are provided forrotating the inner container 70 about the axis 82.

Means which may include the resilient supporting means 60 and thechamber 83 in the inner container 70 are provided for positioningarticles in the chamber 83 with the composite center of gravity of thearticles approximately in a plane 84 perpendicular to the axis 82 at adistance from the pivot 15 (85) equal to the moment of inertia of thesuspended assembly 81 divided by the product of its mass and thedistance from its center of gravity 86 to the pivot 15 (85), plusapproximately l1 percent of the axial depth (73 to 72) of the chamber83. The composite center of gravity of the articles should be withinabout 18 percent, and preferably within about 14 percent of the axialdepth of the chamber 83 of the optimum plane 84.

Friction means 21, 41 engageable with the universal pivot 15 preferablyare provided for reducing the gyration of the suspended assembly 81during rotation of the inner container 70 while passing through acritical speed. The universal pivot 15 preferably comprises twoperpendicular pivotal connections 18e-19, 34-35 including a trunnionmember 35 connected to the suspended assembly at 36 and pivotablyreceived by a horizontal bearing 34 in the universal pivot connector 15and a vertical shaft 19 in the universal pivot connector 15 pivotablyreceived by a bearing 1 8 in the frame 11, the pivot axis in the frame11 intersecting the pivot axis-of the trunnion member 35 as is indicatedat 85. The friction means 21, 41 are engageable with each pivotalconnection as is indicated at 2G, 24 and 40, 44.

The resilient supporting means preferably comprises the compressionspring 60 connected (62) to the frame 11 and supporting the suspendedassembly 81 at a position 61 vaway from the pivot 15, from beneath thesuspended assembly 81 by providing a substantially vertical upward forcethrough the substantially horizontal axis 82. The compression spring 60preferably is so constructed as to provide a higher critical speed ofrotation for the inner container 70 of less than about 90 revolutionsper minute.

-Resilient positioning means 65-65 are connected between the frame 11and the suspended assembly 81 at a position circumferentially spacedvfrom the resilient sup porting means 60, for confining the gyration ofthe suspended assembly 81 to positions substantially above the resilientsupporting means 60.

A laundry machine 10 for washing laundry as well as centrifugallyextracting washing fluid from the laundry preferably includes also asupport member 63, connected (64) to the frame 11 in a position tosupport and restrain the gyration of the suspended assembly 81 duringwashing, the position of the support member 63 being beyond the range ofgyration of the suspended assembly 81 during extraction.

The reference characters in the above summary indicate generally theprimary components shown in the drawings corresponding to the recitedfeatures, to facilitate understanding of the claims. The referencecharacters are used merely by way of example, however, and not in anylimiting sense. v

While the form of the invention herein disclosed constitutes a preferredembodiment, it is not intended to describe all of the possibleequivalent forms or ramifications of the invention. It will beunderstood that the words used are words of description rather than oflimitation, and that various changes may be made without departing fromthe spirit or scope of the invention herein disclosed.

What is claimed is:

l. A centrifugal extractor comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivot; saidsuspended assembly comprising an outer container and an inner containertherein,

Veach substantially symmetrical about a substantially horizontal axis;resilient supporting means connected to said frame and supporting saidsuspended assembly at a position away from said pivot; means forrotating said inner container about said axis; said inner containerdefining a chamber including space for containing articles therein, thecenter of said space lying within about 18 per cent of the axial depthofsaid chamber of a plane perpendicular to said axis at a distance fromsaid pivot equal to the moment of inertia of said suspended assemblydivided by the product of its mass and the distance from its center ofgravity to said pivot, plus approximately l1 percent of the axial depthof said chamber. p

2. A centrifugal extractor comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivot; saidsuspended assembly comprising an outer container and an inner containertherein, each substantially symmetrical about a substantially horizontalaxis; resilient supporting means connected to said frame and supportingsaid suspended assembly at a position away from said pivot; means forrotating said inner container about said axis; friction means engageablewith said universal pivot for reducing the gyration of said suspendedassembly during rotation of said inner container while passing through acritical speed; said inner container defining a chamber including spacefor containing articles therein, the center of said space lying withinabout 18 percent of the axial depth of said chamber of a planeperpendicular to said axis at a distance from said pivot equal to themoment of inertia of said suspended assembly divided by the product ofits mass and the distance from its center of gravity to said pivot, plusapproximately l1 percent of the axial depth of said chamber.

3. A centrifugal extractor comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivotcomprising two perpendicular pivotal connections; said` suspendedassembly comprising an outer container and an inner container therein,each substantially symmetrical about a substantially horizontal axis;resilient supporting means connected to said frame and supporting-saidsuspended assembly at a position away from said pivot; means rforrotating said inner container about said axis; friction means engageablewith each said pivotal connection for reducing the gyration of saidsuspended assembly during rotation of said inner container while passingthrough a critical speed; said inner container defining a chamberincluding space for containing articles therein, the center of saidspace lying within about 18 percent of the axial depth of said chamberof a plane perpendicular to said axis at a distance from said pivotequal to the moment of inertia of said suspended assembly divided by theproduct of its mass and the distance from i-ts center of gravity to saidpivot, plus approximately l1 percent of the axial depth of said chamber.

4. A centrifugal extractor comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivotconnector by means of a trunnion member connected to said suspendedassembly and pivotably received by a horizontal bearing in saidconnector and a vertical shaft in said connector pivotably received by abearing in said frame, the pivot axis in said frame intersecting thepivot axis of said trunnion member; said suspended assembly comprisingan outer container and an inner container therein, each substantiallysymmetrical about a substantially horizontal axis; resilient supportingmeans comprising a compression spring connected to said frame andsupporting said suspended assembly, at a position away from said pivot,from beneath said suspended assembly by providing a substantiallyvertical upward force through said substantially horizontallast-mentioned axis, so constructed as -to provide a higher criticalspeed of rotation for said inner container of less than about 90revolutions per minute; means for rotating said inner container aboutits axis; friction means engageable at each said bearing for reducingthe gyration of said suspended assembly during rotation of said innercontainer while passing through a critical speed; resilient positioningmeans connected between said frame and said suspended assembly at aposition circumferentially spaced from said resilient supporting means,for conning the gyration of said suspended assembly to positionssubstantially above said resilient supporting means; said innercontainer defining a chamber including space for containing articlestherein, the center of said space lying within about 18 percent of theaxial depth of said chamber of a plane perpendicular to said axis at adistance from said pivot equal to the moment of inertia of saidsuspended assembly divided by thevproduct of its mass and the distancefrom its center of gravity to said pivot, plus approximately 1l percentof the axial depth of said chamber.

5. A laundry machine for washing laundry and centrifugally extractingwashing iiuid therefrom comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivot; saidsuspended assembly comprising an outer container and an inner containertherein, each substantially symmetrical about a substantially horizontalaxis; resilient supporting means connected to said frame and supportingsaid suspended assembly 'at a position away from said pivot; means forrotating said inner container about said axis for washing said laundryand for extracting washing iiuid therefrom; said inner containerdefining a chamber including space for containing said laundry therein,the center of said space lying within about 18 percent of the axialdepth of said chamber of a plane perpendicular to said axis at adistance from said pivot equal to the moment of inertia of saidsuspended assembly divided by the product of itsl mass and the distancefrom its center of gravity to said pivot, plus approximately 11 percentof the axial depth of said chamber.

6. A laundry machine for washing laundry and centrifugally extractingwashing uid therefrom comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivot; saidsuspended assembly comprising an outer container and an inner containertherein, each substantially symmetrical about a connected to said frameand supporting said suspended assembly at a position away from saidpivot; means for rotating said inner container about said axis forwashing said laundry and for extracting washing fluid therefrom; 'ictionmeans engageable with said universal pivot for reducing the gyration ofsaid suspended assembly during rotation of said inner container whilepassing through a critical speed; said inner container defining achamber including space for containing said laundry therein, the centerof said space lying within about 18 percent of the axial depth of saidchamber of a plane perpendicular to said axis at a distance from saidpivot equal to the moment of inertia of said suspended assembly dividedby the the axial depth of said chamber. i

7. A laundry machine for washing laundry and centriugally extractingWashing u'id thererom comprising:

a supporting frame; a suspended assembly connected at one end to saidframe by a universal pivot comprising ltwo perpendicular pivotalconnections; said suspended assembly comprising an outer container andan ,inner container therein, each substantially symmetrical about asubstantially horizontal axis; resilient supporting means connected tosaid frame and supporting said suspended assembly at a position awayfrom said pivot; means for rotating said inner container about said axisfor washing said laundry and for extractingv washing uid therefrom;friction means engageable at each said pivotal connection for reducingthe gyration of said suspended assembly during rotation of said innercontainer while passing through a critical speed; a support memberconnected to said frame in a position to support and restrain thegyration of said suspended assembly during washing, said position beingbeyond the range of gyration of said sus- I' pended assembly duringextraction; said inner container defining a chamber including .space forcontaining said laundry therein, the center of said space lying withinabout 18 percent of the axial depth of said chamber of a planeperpendicular to said axis at a distance from said pivot equal to themoment of inertia of said suspended assembly divided by the product ofits mass and the distance from its center of gravity to said pivot, plusapproximately ll percent of the axial depth of said chamber.

8. A laundry machine for washing laundry and centrifugally extractingwashing uid therefrom comprising: a supporting frame; a suspendedassembly connected at one end to said frame by a universal pivotconnector by means of a trunnion member connected to said suspendedassembly and pivotably received by a horizontal bearing in saidconnector and a vertical shaft in said connector pivotably received by abearing in said frame, the pivot axis in said frame intersecting thepivot axis of said trunnion member; said suspended assembly comprisingan outer container and an inner container therein, each substantiallysymmetrical about a substantially horizontal axis; resilient supportingmeans comprising a compres. sion spring connected to said frame andsupporting said suspended assembly at a position away from said pivot,from beneath said suspended assembly by providign a substantiallyvertical upward force through said substantially horizontal lastmentioned axis, so construeted as to provide a high critical speed ofrotation for said inner container of less than about 90 revolutions perminute; means for rotating said inner container about its axis forwashing said laundry and for extracting washing tiuid therefrom;friction means engageable at each said bearing for reducing the gyrationof said suspended assembly during rotation of said inner container whilepassing through a critical speed; resilient positioning means connectedbetween said frame and said suspended assembly at a positioncircumferentially spaced from said substantially horizontal axis;resilient supporting means resilient supporting means, for confining thegyration of 1 1 said suspended assembly to positions substantially abovesaid resilient supporting means; a support member connected to saidframe in a position to support and restrain the gyration of saidsuspended assembly during washing, said position being beyond the rangeof gyration of said suspended assembly during extraction; said innercon- References Cited in thefile of this vpatent UNITED STATESPA'TENTS'l Cairns -,....V;Aug. 13, 1889 Bradbury Feb. 11941 Kirby Mar.5," 1946 Contermanl June 27 ,i v1950 Kreitchman an 13, 1953 O'Connor May5, 1953 Meyer v.. Apr. 26, 1955 FOREIGN PAIENTS l-

